1. Field of the Invention
The invention relates in general to communication transmission systems for electromagnetic waves comprising a transmitter in which the signal to be transmitted is modulated onto a carrier and to the transmission and reception antennas with a radio link hop lying between them and to a receiver which includes an allocated diversity receiver in which the received signal is converted into an IF level and is demodulated.
2. Description of the Prior Art
On radio links which do not have access to energy supply networks, radio systems are supplied by way, of example, by solar systems, wind generators or by diesel generators. High acquisition and operating costs of such systems require that the lowest possible power consumption of the radio apparatus occur. For analog FM systems and digital systems up to 34M bits per second an adequately low power consumption can be achieved with standard systems concepts. For solar systems, for example, power consumption can be less than 300 watts for two way 1+1 connections without significant departure from the CCIR quality demands for transmission systems. Fast digital systems as, for example, 140M bits per second present a number of problems and these require adaptive base band equalizers and space diversity because of their sensitivity to fading and also are dependent on fast logic which require high power consumption.